Baby boomers have been known for a lot of things, but religious observance is not especially one of them.

As they began to come of age in the tumult that was the 60s, many boomers were more likely to have a copy of “Steal This Book” shoved into the ripped back pocket of their jeans than the Good Book. “Just as the boomers’ parents had been largely responsible for the postwar surge on religiosity, the boomers themselves were largely responsible for the collapse in religiosity two decades later,” notes “American Grace,” a book about American religious practices.

But over time, even members of a generation of iconoclasts, or self-styled ones, might one morning come to find themselves in the kind of a place where icons are revered, not smashed.

Academics and pastors alike have long known that as people get older, they tend to become more religious, and it turns out that boomers are no exception. A survey conducted by Gallup in 2010 found that people ages 50 to 64 were more likely to say they frequently went to church, temple or mosque than those 18 to 29 did. The figures were 43 percent versus 35 percent, and for the group containing the oldest segment of the baby boom population – 65 and up – the figure was 53 percent.

More to the point, when pollsters looked at how often baby boomers said they went to church now and compared that with what they said when they were younger, they found a difference, said Frank Newport, Gallup’s editor in chief, who has a book coming out about religion. “They were less religious, that group, 20 years ago than they are now,” he said.

A couple of cautions. The findings apply best to Christians and Jews, experts say. And the pollsters did not station workers by church doors with clickers and count the boomers making their way in. They simply called people up and asked them questions, raising the possibility that some tried to make themselves look better.

Think about it: when Mr. or Ms. Gallup calls, are you really going to say that the last time you went to church was three years ago? Surely meaning to go must count for something. Of course, maybe a lot of these people had been fibbing for years about going to Woodstock, and eased their conscience by giving the pollsters a more reliable account about church.

What may explain why a boomer would become more religious? Part of it may be simply a function of maturation. “Marriage, having children, homeownership, and simply having roots in a community are all factors that nudge people toward religion,” David E. Campbell, the Notre Dame professor who wrote “American Grace” with Robert D. Putnam, said in an e-mail.

Then there is that other little matter: mortality, said Wade Clark Roof, a professor of religion and society at the University of California, Santa Barbara, who has written extensively about baby boomers.

“They have all been through it, or are in the middle of it,” he said. “Their parents are dying off. So the reality of mortality has hit them. When they were young, they thought they would live forever. But they know better now.”

Which is not to say that churches should be bracing themselves for boomers to rush the doors. The distrust in institutions like organized religion born in the 60s is not likely to be cast off entirely. So even as baby boomers return to the church, it is hard to imagine they will reach the same numbers as the generation before them.